A team of astronomers including those from the University of Tokyo created the first-ever map of magnetic field structures within a spiral arm of our Milky Way galaxy. Previous studies on galactic magnetic fields only gave a very general picture, but the new study reveals that magnetic fields in the spiral arms of our galaxy break away from this general picture significantly and are tilted away from the galactic average by a high degree. The findings suggest magnetic fields strongly impact star-forming regions which means they played a part in the creation of our own solar system.
It might come as a surprise to some that magnetic fields can exist on scales larger than a planet. Most of our daily experience with magnetic fields involves either sticking things to our refrigerator, or perhaps using a compass to point north. The latter shows the existence of magnetic fields generated by our planet. Our sun also creates a vast magnetic field, and this can affect phenomena like solar flares. But magnetic fields that span the galaxy are almost too large to comprehend, and yet they likely have a role in the formation of stars and planets.
“Until now, all observations of magnetic fields within the Milky Way led to a very limited model that was uniform all over and largely matched the disc shape of the galaxy itself,” said Assistant Professor Yasuo Doi from the Department of Earth Science and Astronomy. “Thanks in part to telescope facilities at Hiroshima University capable of measuring polarized light to help us ascertain magnetic signatures, and the Gaia satellite launched by the European Space Agency in 2013, which specialized in measuring the distances to stars, we are able to build a better model with finer details in three dimensions. We focused on a specific area, the Sagittarius arm of our spiral galaxy (we are in the neighboring Orion arm) and found the dominant magnetic field there breaks away from the plane of the galaxy significantly.”
Previous models and…